Quote:NEW DELHI: One of the two brand new Boeing 787 Dreamliners that Air India got last month is cooling its heels at Delhi airport since last week after its front cargo door developed a snag and now cannot be shut for the plane to get airborne. The aircraft, VT-ADN, was the second Dreamliner that AI got from Boeing on September 19, 11 days after getting the first one VT-ANH.

Sources say this Dreamliner remained in commercial domestic service barely for few days. Last Friday its front cargo hold door hinge 'disintegrated', while the baggage was being offloaded after the plane landed from Chennai. It has been grounded since then.

"The thing is that nothing hit the cargo door and the part simply disintegrated on its own. Boeing is to send a replacement part from Europe to Delhi via London but it hasn't come so far. The airline gets a bad name because of the composite material trouble (the light material B-787 is made of)," said sources.

AI spokesman G P Rao said, "VT-AND aircraft is on ground at Delhi due to disintegration of forward actuator arm bearing of forward cargo door. The spares are scheduled to arrive on Wednesday and the aircraft will return to service on Thursday. Boeing is investigating the incident along with DGCA."

What a strange incident. Can someone with more techincal expertise perhaps explain what could cause this bearing to suddenly disintegrate?

Quoting aeroblogger (Thread starter):
What a strange incident. Can someone with more techincal expertise perhaps explain what could cause this bearing to suddenly disintegrate?

Until we see any more cases like this, operator error or sabotage are about the only possibilities. I have yet to work on a 787, but I have a fair bit of time with Boeing products, and these things really don't just "fall apart" on their own.

Completely inaccurate reporting of the situation is always a possibility as well.

I'm not really a Boeing fan any more than Airbus and I'm not nationalistic in the least, but this seems pretty sensational - and not in a good way. I'd bet a few bucks that this has more to do with Air India than with Boeing.

AI might not be the brightest bulb on the aviation Christmas tree but I will give them a little more credit. It is not unheard of to have issues on a new type especially with new materials. Just because none of the other airlines have had this problem does not mean it is not possible.

Quoting Darksnowynight (Reply 1): I have yet to work on a 787, but I have a fair bit of time with Boeing products, and these things really don't just "fall apart" on their own.

If it just is not correctly mounted it can sometimes happen. Component can break for many reasons, and maybe there was some impact at the previous flight etc., This is no big deal!!
Just shame that the plane has to be taken out of operation.

Oh sure, it just miraculously disintegrated.
And that particular media source has already blamed it on the composite structure.
Have we had a similar report from ANA, JAL, or Ethiopian? I certainly haven't heard of it.

Maybe they're just trying to strong arm Boeing Finance into somehow financing another 787 they cannot afford to take delivery of.

Quoting Asiaflyer (Reply 6):and maybe there was some impact at the previous flight etc.

and that might explain the "disintegration." Maybe if the part were aluminum they would have bent it severely and then it would have fractured and instead it (more dramatically) fractured after no ductile failure. Either way, it was a result of misuse if that's the case.

It may well be a design issue and something that Boeing has to correct, but Air India's wording in this has me pretty skeptical.

Quote:VT-AND aircraft is on ground at Delhi due to disintegration of forward actuator arm bearing of forward cargo door. The spares are scheduled to arrive on Wednesday and the aircraft will return to service on Thursday. Boeing is investigating the incident along with DGCA.

What causes you to be skeptical about this? Do you think AI has randomly decided to ground the aircraft without any failure? Do you think that they are lying about when the spare parts will come in?

Such a mechanism appears to be Boeing's standard design for opening lower lobe cargo doors. One of the arms is driven via angular displacement about a pivot point, which straightens the linkage opening the door. It appears one of the bearings in this linkage may have failed.

Regards, JetMech

JetMech split the back of his pants. He can feel the wind in his hair.

This sounds like a situation where someone drove a baggage truck into the plane and then said "I didn't do anything it just fell apart!" whilst looking shifty and hoping noone will notice at tear a strip off them

Quoting aeroblogger (Thread starter):Can someone with more techincal expertise perhaps explain what could cause this bearing to suddenly disintegrate?

It's not clear. There are several bearings in the opening linkage, as previously posted. In addition, the door itself attaches to the fuselage by way of a huge piano hinge.

Quoting Stitch (Reply 13):
Do we know for a fact that this part is made out of CFRP, or are we just assuming it is because it's a 787?

We know for a fact that it's *not* CFRP. None of the hinge mechanisms or actuator links are.

What makes me very suspicious of this as a ramp-rash incident is that "disintegration" implies a catastrophic failure, which implies an overload. Thanks to maximum wind requirements, there's really no way to overload the door in normal operations. It could be a flat-out faulty part, but that should have showed up during pre-delivery testing. The plane is too new to have a fatigue failure and that generally leads to crack-through, not disintegration. Cargo doors are notorious ramp-rash magnets.

Quoting golfradio (Reply 5):AI might not be the brightest bulb on the aviation Christmas tree but I will give them a little more credit. It is not unheard of to have issues on a new type especially with new materials. Just because none of the other airlines have had this problem does not mean it is not possible.

Around here they're the-boy-who-cried-wolf. Just about anything they say will be met with incredulity.

Quoting tdscanuck (Reply 15):
We know for a fact that it's *not* CFRP. None of the hinge mechanisms or actuator links are.

What makes me very suspicious of this as a ramp-rash incident is that "disintegration" implies a catastrophic failure, which implies an overload. Thanks to maximum wind requirements, there's really no way to overload the door in normal operations. It could be a flat-out faulty part, but that should have showed up during pre-delivery testing. The plane is too new to have a fatigue failure and that generally leads to crack-through, not disintegration. Cargo doors are notorious ramp-rash magnets.

Thank you for this highly informative post... It certainly is a very intriguing issue.

Quoting DocLightning (Reply 20):Does metal even "disintegrate" without a direct blow? Cracking or bending I can see, but turning into a shower of little bits? That strikes me as an odd thing for metal to do.

I wouldn't take their choice of word too literally. I would bet a beer that it actually cracked into two or three pieces.

First of all, this is AI. They have been trying to blame anyone and everyone for their own problems. The likelyhood of this metal part simply "disintergrating" without some type of outside influence (accident, ramp rash, wind overload, etc.) is ZERO.

The pictures in reply # 11 are not a B-787, but they do show how the arms are attached to the cargo door. I say it is not a B-787 because UA just recently took delivery of their first one, and the interior shot and shot of the outside showing the door locking cams shows some wear and dirt, so it may be a B-767 or a B-777. Also that is not a GEnx-2B engine.

Quoting StuckInCA (Reply 3): I'd bet a few bucks that this has more to do with Air India than with Boeing.

Quoting phxa340 (Reply 2):Pretty sure the airline gets a bad name from Air India and Air India alone.

Quoting scouseflyer (Reply 12):This sounds like a situation where someone drove a baggage truck into the plane and then said "I didn't do anything it just fell apart!" whilst looking shifty and hoping noone will notice at tear a strip off them

Quoting SSTeve (Reply 16):Around here they're the-boy-who-cried-wolf. Just about anything they say will be met with incredulity.

Isn't it amazing how you can make such comments without even knowing the full story....? Just because AI has been having bad publcity on various fronts doesn't mean you can jump to such conclusions.....bear in mind that they've been operating planes for well over 60 years now.....

Quoting golfradio (Reply 5):Just because none of the other airlines have had this problem does not mean it is not possible.

Quoting KC135TopBoom (Reply 23):First of all, this is AI. They have been trying to blame anyone and everyone for their own problems. The likelyhood of this metal part simply "disintergrating" without some type of outside influence (accident, ramp rash, wind overload, etc.) is ZERO.

Wow! You seem to know more about the 787 than Boeing themselves

25 KC135TopBoom
: No, I do not. But I know a BS story when I see one. Metal parts just do not "disintergrate" without something happening to them, that was my point.

26 n797mx
: Knowing AI and its history with Boeing I wouldn't put sabotage out of the question so they can get a discount of sorts on the 787...

27 AWACSooner
: This incident should be worth about 2 dozen free 787's in AI's eyes...

28 Gr8Circle
: Well, that just reinforces what I said in my earlier point.......you seem to know more than all the experts out there, without even having seen anyth

29 aerobalance
: Have you been to India? Have you done business with any entities in India? I've done business with their government in the aerospace field - it's tru

30 Gr8Circle
: Much more than you, having been born and brought up in Mumbai I know very well about the problems of corruption in India.....I was referring to the a

31 manny
: Wow..the choir preaching against AI is in full swing. It so co-ordinated and synchronized it would put a symphony to shame!

32 xdlx
: The day India shows the world they are capable of supporting an aerospace product correctly.... the tide of "remarks and conclusions" will turn. Until

33 Aesma
: Well the problem is that the story we get from India is also making assumptions that seem very unlikely. So ensues a backlash.

34 Stitch
: A valid point, but a few (including "sources" quoted by The Times of India) jumped to the conclusion that this was a failure of a CFRP part unique to

35 aeroblogger
: Air India's maintenance department is one of the best... There may be all kinds of shenanigans at AI when it comes to financing and management, but I

36 Revelation
: Ok, since we should try hard to give AI the benefit of the doubt, is there any ambiguity to the use of the word 'disintegration'? I am an American wh

37 aeroblogger
: I wouldn't know - I did my schooling in the US, so the word means definition (b) to me, and I've never actually heard anybody use the word "disintegr

38 Revelation
: LOL, surely the Indians I've met are much more polite than us Americans - we'd say "the ****ing piece of **** broke!"

39 tdscanuck
: If this were any other airline, I'd still suspect ramp rash as the primary cause absent other data. Spontaneous failure of new metal components in so

40 StuckInCA
: I don't see how you could claim that based on my remarks. The statements from India had sensaitonal words such as "disintegrated." Even if a part fai

41 aeroblogger
: I wouldn't consider the word "disintegrated" sensational. I would consider it descriptive. If that's what happened, that's what I'd expect any organi

42 zeke
: The 787 is still a newish aircraft, not a lot have been built. There are plenty of ADs issued in the past where the manufacturer got it wrong in the

43 BEG2IAH
: I wouldn't say "disintegration" is the most sensationalist word in this press release. The "light material B-787 is made of" is. If the actuator took

44 Stitch
: Whomever the "sources" are quoted in the article, they said that nothing hit the door, just that it failed sometime after opening, so that would rule

45 KC135TopBoom
: The arm for the cargo door is just an updated version of the cargo door arm Boeing started putting on the KC-135 back in 1955. That may be true, but

46 kanban
: If AI files a warranty claim, they will be returned, if not the on site Boeing rep may request or just photograph the units. (and probably already has

47 lightsaber
: The only way I know is rapid formation of ice inside a porous metal or a volume inside the metal. For example, during climb. Oh, one can do it with e